Percolating at the back of my brain somewhere is an evolving composite answer to the question of "Why we are dry" - epidemiologically speaking. Many, probably most of the pieces are known but I am always on the lookout for additional clues. And yes, I know this study is just 15 rats for 7 days but it's suggestive and I'd like to get some sense of the potential relevance.
My question: Where do normal people typically get exposure to ELF magnetic fields?
The effect of extremely low frequency magnetic field on the conjunctiva and goblet cells.
Keklikci U, Akpolat V, Ozekinci S, Unlu K, Celik MS.
Curr Eye Res. 2008 May;33(5):441-6.
PURPOSE: The aim of this study was to examine the effects of extremely low frequency magnetic field (ELF MF) on the conjunctiva and goblet cells density.
METHODS: Thirty adult female Spraque Dawley rats were assigned to one of two groups, each containing 15 rats. The experimental group received magnetic field 4 hr/day for 7 days. The second group received standard laboratory care and served as a control. The specimens were evaluated by light microscopy for goblet cell density, conjunctival edema, inflammation, and fibroblast proliferation.
RESULTS: In ELF MF exposure group rats, the number of goblet cells was less than the control group. We also observed a significant difference between ELF MF exposure group and control group in terms of goblet cell density (p = 0.010). The ELF MF exposure group manifested conjunctival edema and inflammation compared to the control group (p < 0.001 and p = 0.003). There was no statistical difference between the groups for fibroblast proliferation (p = 0.422).
CONCLUSION: This study suggests that ELF MF exposure leads to morphological alterations of the conjunctiva and reductions in the number of goblet cells. We believe that ELF MF may cause dry eye symptoms.
3 comments:
Where would people come in contact with ELF-MF? Is this the same as wireless internet? I've just had that installed, seem to have worse dry eye symptoms, but hadn't connected the two happenings until I read this abstract.
Marjorie Bayes
Bay View, Michigan
Bayeswashburn@cmac.com
My brother is an electrictian in Ireland where the voltage are 230 and in the States are 110.
EMF is a electro magnetic force. It a magnetic field that AC current gives off when it moves from one point to another.
Such as once the kettle goes on it gives off EMF as the current moves down the cable.
In Ireland the strongest point of ELF_MF comes from the socket board, but he doesn't think it would be strong enough to have any impact on poeple. In America the voltage is lower and he doesn't know how houses are wired.
If you want to see if something gives of ELF get a compass. It will point one direction. Move it up to the electric socket, when the compass starts to move then you know the EFF Magnet Field comes out that far. If it does not move then the ELF-MF does not extend outside the socket and remains in the cable in the wall.
In San Francisco where I live the place where we would experience the most ELF-MF (possibly) is from those overhead cables that run into houses...how much and if we do would depend on how much power was going through them, that is if they power a whole street or just one house. This could be checked with a compass I guess!
The internet wireless does not work on these waves...it has something to do with radio waves.
So this is how I understand what my brother told me.
Bernadette M
San Francisco
Did the article say exactly what frequency range they were talking about? I'm wondering how they defined ELF.
According to the WHO website, ELF is defined as 50-60 Hz. OSHA defines it as 100-300Hz.
60 Hz is what our power is transmitted at, so any exposure would be from power lines or electricity flowing through your house.
People have been studying the connection between power lines and cancer and other health problems for some time now.
I attended a lecture on this topic when I was in graduate school (engineering). They had found higher incidents of certain childhood cancers in a neighborhood with lots of power lines. They came to the conclusion that it wasn't the power lines that caused the problem, but pollution from the 6-lane highway that the power lines ran alongside.
I'm guessing that, in this study, the rats were exposed to a very strong field, at close range, and that none of us are ever going to experience a comparable level of exposure.
Bernadette is right. This has nothing to do with wireless internet.
Hope that's helpful.
Teri
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